<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="https://cdn.jsdelivr.net/npm/vue@2.6.10/dist/vue.js"></script>
</head>

<body>
    <div id="app">
        <button @click="firstName='li'">计算</button>
        <h2>全名是{{fullName}}</h2>
        <h2>全名是{{fullName}}</h2>
        <h2>全名是{{fullName}}</h2>
        <h2>全名是{{fullName}}</h2>
    </div>
    <script>
        Vue.config.productionTip = false;
        
        const vm = new Vue({
            el: "#app",
            data() {
                return {
                    firstName: "Wang",
                    lastName: "zhongwang",
                }
            },
            computed:{
                fullName:{
                   get(){
                    console.log(getter);
                    return(
                        this.firstName.toLowerCase()+" "+this.lastName.toLowerCase()
                    )
                   },
                   set(val){
                    console.log("setter",val);
                    // split 切割
                    this.firstName = val.split(" ")[0];
                    this.lastName = val.split(" ")[1];
                   }
                    
                }
            }
        })
</script>
</body>

</html>